From: Fenghua Yu <fenghua...@intel.com> When a new mm is created, its PASID should be cleared, i.e. the PASID is initialized to its init state 0 on both ARM and X86.
Reviewed-by: Tony Luck <tony.l...@intel.com> Signed-off-by: Fenghua Yu <fenghua...@intel.com> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org> --- This patch was part of the series introducing mm->pasid, but got lost along the way [1]. It still makes sense to have it, because each address space has a different PASID. And the IOMMU code in iommu_sva_alloc_pasid() expects the pasid field of a new mm struct to be cleared. [1] https://lore.kernel.org/linux-iommu/ydgh53acqht+t...@otcwcpicx3.sc.intel.com/ --- include/linux/mm_types.h | 1 + kernel/fork.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 0974ad501a47..6613b26a8894 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -23,6 +23,7 @@ #endif #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) +#define INIT_PASID 0 struct address_space; struct mem_cgroup; diff --git a/kernel/fork.c b/kernel/fork.c index d66cd1014211..808af2cc8ab6 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -994,6 +994,13 @@ static void mm_init_owner(struct mm_struct *mm, struct task_struct *p) #endif } +static void mm_init_pasid(struct mm_struct *mm) +{ +#ifdef CONFIG_IOMMU_SUPPORT + mm->pasid = INIT_PASID; +#endif +} + static void mm_init_uprobes_state(struct mm_struct *mm) { #ifdef CONFIG_UPROBES @@ -1024,6 +1031,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm_init_cpumask(mm); mm_init_aio(mm); mm_init_owner(mm, p); + mm_init_pasid(mm); RCU_INIT_POINTER(mm->exe_file, NULL); mmu_notifier_subscriptions_init(mm); init_tlb_flush_pending(mm); -- 2.30.1
